Recent advances in coating technology have provided coatings which are suitable for use over various substrates which are difficult to coat and which have many different properties. Coatings of excellent appearance, a high order of durability and having the ability to withstand severe environmental conditions have been obtained. Among the more advanced coatings are those employed on vehicles, such as automobiles, where good appearance must be maintained over long periods despite exposure to weather and various forms of attack during use.
Thermosetting resins have long been useful as coating materials. Such compositions can be tailored to achieve a great variety of properties, including high strength, extensibility and durability. While such coating compositions have many excellent properties, a recurring problem with such resins, particularly thermosetting resins which are cured by aminoplast resins has been the instability of the cured resins resulting in a substantial loss of gloss over periods of time.